title: B-type natriuretic peptide at the early stage of univentricular circulation reflects inadequate adaptation to volume overload.
abstract: BACKGROUND
  Recent studies showed that children with univentricular heart have elevated plasma B-type natriuretic peptide (BNP) levels prior to bidirectional cavopulmonary anastomosis (BDCPA). However, it remains to be established whether BNP levels reflect the degree of hemodynamic overload and relate to long-term outcome in univentricular circulation.
  
  
  METHODS
  Fifty one consecutive children with functionally univentricular heart prior to BDCPA were studied. All patients underwent cardiac catheterization and BNP measurement. Ventricular end-systolic wall stress (ESWS) and end-diastolic wall stress (EDWS) were calculated from cardiac catheterization data.
  
  
  RESULTS
  Median age was 1.1 years and 34% were female. Median BNP concentration was 90.4 pg/ml. Patients with high BNP (≥ 100 pg/ml) had higher pulmonary to systemic flow ratio (p = 0.014), a greater end-diastolic volume (p=0.009), more severe atrioventricular valve regurgitation (p= 0.02) and lower ventricular mass to end-diastolic volume ratio (p=0.006). BNP levels strongly related to EDWS (r = 0.75, p< 0.0001) and ESWS (r = 0.63, p < 0.0001). During median follow-up period of 3.2 years, 15 patients died and one underwent heart transplantation for refractory heart failure. On multivariate Cox regression analysis, high BNP concentration was an independent predictor of death or transplantation (HR 3.05, CI: 1.06-8.83, p = 0.04).
  
  
  CONCLUSIONS
  High BNP concentration at the first palliative stage towards Fontan circulation reflects high wall stress due to high volume load and insufficient ventricular hypertrophy. Moreover, high BNP levels at this stage were independently related to long-term outcome. BNP may be used as a guide to identify patients with high workload due to inadequate adaptation to hemodynamic load, who are at high risk.
authors.affiliation: The Department of Pediatric Cardiology, Chiba Children's Hospital, Chiba-city, Chiba, Japan. inuzukar-tky@umin.ac.jp
authors.forename: Ryo
authors.initials: R
authors.lastname: Inuzuka
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Tatebe
authors.forename: Sadae
authors.initials: S
authors.lastname: Wakiguchi
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Nakajima
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ohtsu
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Dimopoulos
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Aotsuka
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D015415:Biomarkers / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D018729:Fontan Procedure; D006333:Heart Failure / Q000097:blood* / Q000175:diagnosis; D006801:Humans; D007223:Infant; D008297:Male; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D013318:Stroke Volume / Q000502:physiology*; D016277:Ventricular Function, Left / Q000502:physiology
chemical_list: D015415:Biomarkers; D020097:Natriuretic Peptide, Brain